Homebrew PCBs

Stefan Trethan wrote:

> Well, you can try.
> I still think direct printing (drum to copper) is a no-go for many reasons.
> one beeing the drum will be damaged by the board edges, also the corona  
> thing will not work properly.
> 
> The silicone roller thing Denny is testing works so far, but for me it  
> seems to much work to build compared with the little more effort of  
> silicone paper.
> 
> ST


   A light file pass then tape over the edges will easily protect the drum for 
the most part.  While it may still not last forever printing to scrubbed copper, 
the $50 investment in a secondary laser and a $25 cartridge now and then would 
be a great investment vs all the labor in making and transferring from paper. 
And if you recall the very end of our previous thinking through of modifying a 
laser printer, I think a wire and conductive foam may well work for a bottom 
corona type printer.  But top corona shouldn't even need that.  Explains why I 
had printed text even over 3 or 4 inch sections of foil, only problems were 
wrinkling in the center since I just taped the edges down and flaking from not 
enough fusing and very smooth foil.  First won't happen with a board and second 
is easy to fix.  Looking for the AL foil to refresh my testing again and see 
just how large a sheet I can print.  If it'll do 6"x6" with very little extra 
paper area, then it's probably working like I'm thinking and would work fine for 
about any size board.  Just have to find my spray mount to make it stick to some 
paper.

   If the roller works it wouldn't be that hard either really.  About every kind 
of roller you could ever think of is already made for one printing industry or 
another.  It's also easy enough to skin an old dot matrix printer platen with 
other materials.  Hardest part would be fitting one to an already built printer, 
a little looking around should find a decent match of dot matrix platen to XXX 
laser though for minimum work.

Alan